Dark Matter Decaying into a Fermi Sea of Neutrinos

Abstract

We study the possible decay of a coherently oscillating scalar field, interpreted as dark matter, into light fermions. Specifically, we consider a scalar field with sub-eV mass decaying into a Fermi sea of neutrinos. We recognize the similarity between our scenario and inflationary preheating where a coherently oscillating scalar field decays into standard model particles. Like the case of fermionic preheating, we find that Pauli blocking controls the dark matter decay into the neutrino sea. The radius of the Fermi sphere depends on the expansion of the universe leading to a time varying equation of state of dark matter. This makes the scenario very rich and we show that the decay rate might be different at different cosmological epochs. We categorize this in two interesting regimes and then study the cosmological perturbations to find the impact on structure formation. We find that the decay may help alleviating some of the standard problems related to cold dark matter.

8 pages, 3 figures, accepted for publication in Phys. Rev. D

References in corpus (17)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Large-scale instability in interacting dark energy and dark matter fluids
• Dynamics of dark energy with a coupling to dark matter
• A Non-thermal WIMP Miracle
• Adiabatic instability in coupled dark energy-dark matter models
• Dark Matter Signals from Cascade Annihilations
• Decaying Dark Matter in Light of the PAMELA and Fermi LAT Data
• Dynamics of Interacting Quintessence Models: Observational Constraints
• Neutrino Dark Energy -- Revisiting the Stability Issue
• Where in the String Landscape is Quintessence
• Neutrino Signals from Dark Matter Decay
• The New DAMA Dark-Matter Window and Energetic-Neutrino Searches
• The Integrated Sachs-Wolfe Effect in Interacting Dark Energy Models
• High-Energy Neutrino Signatures of Dark Matter Decaying into Leptons
• Prospects for Indirect Detection of Sneutrino Dark Matter with IceCube
• Light Dark Matter Detection Prospects at Neutrino Experiments

Cited by in corpus (6)

• Early mass varying neutrino dark energy: Nugget formation and Hubble anomaly
• Origin of Delta N_eff as a Result of an Interaction between Dark Radiation and Dark Matter
• Testing Dark Matter Clustering with Redshift Space Distortions
• How CMB and large-scale structure constrain chameleon interacting dark energy
• Signatures of Light Massive Relics on nonlinear structure formation
• Stable dark matter from Pauli blocking in the degenerate fermion background with Quantum Field Theory